Researchers has taken an intriguing step in the direction of brain computing – a device named memristor that’s able to ‘forget’ memories, just like our brains do.
It’s called a second-order memristor (a mix of “memory” and “resistor“). The clever design mimics a human brain synapse in the way it remembers information, then gradually loses that information if it’s not accessed for an extended period of time.
Right now analogue neurocomputers are hypothetical, because we need to work out how electronics can mimic synaptic plasticity – the way that active brain synapses strengthen over time and inactive ones get weaker.
It’s why we can hang on to some memories while others fade away, scientists think.
In this case, the team used a ferroelectric material called hafnium oxide in place of nanobridges, with an electric polarisation that changes in response to an external electric field. It means low and high resistance states can be set by electric pulses.
“We are going to look into the interplay between the various mechanisms switching the resistance in our memristor,” says physicist Vitalii Mikheev, from MIPT.
“It turns out that the ferroelectric effect may not be the only one involved. To further improve the devices, we will need to distinguish between the mechanisms and learn to combine them.”